At MSU snow, ice and cold are hot science November 24, 2008 by Michael Becker • Published
11/24/08

Experienced backcountry skiers know the sound. It originates deep beneath the snow and resonates through your body, spreading like dread.

WHUMP!

It's the sound of nature removing the linchpin that kept the thousands of tons of snow beneath your skis from sliding down the mountainside. It's the sound of a weak layer breaking.

Montana State University engineering mechanics professor Ed Adams has heard that sound and knows the terror of seeing the snow fracture beneath his skis. Not every whump is followed by an avalanche, Adams said, but it's a powerful warning.

Adams is one of the world's leading avalanche researchers. In addition to the papers he has published, Adams has appeared on national television programs such as Good Morning America and has been featured in such magazines as National Geographic Adventure. He's well-known for his avalanche research methods, which involve a snow-laden hillside, a scientist-filled shack bolted to the slope and some explosives to get things moving.

Adams is also one of a growing number of researchers at MSU who study snow, cold and ice. Cold regions research, otherwise known as cold science, began at MSU just after World War II, when men like Charles Bradley and John Montagne joined the faculty. These soldiers-turned-scientists brought with them intimate knowledge of using avalanches as weapons and a passion for snow, ice and mountains.

Bradley, Montagne and others--in addition to helping found the area's highly successful ski industry--turned the mountains into classrooms, capitalizing on the area's surplus snow and ice and establishing a tradition of internationally recognized snow science work at MSU.

The cold proved a popular subject, attracting students from across the country. Before long, cold science expanded beyond its home in earth sciences, taking root in departments across campus, from engineering to microbiology.

Today, researchers continue to use MSU's surrounding natural laboratory to study everything from the physics of avalanches and global warming to the origins of life on earth--or elsewhere. And when Montana isn't cold enough, those researchers head for places like Antarctica and Alaska, their work boosting the university's reputation as home to some of the world's best cold scientists.

This fall the university opened its new Subzero Science and Engineering Research Facility, in Cobleigh Hall, a one-of-a-kind, 2,700-square-foot complex of cold chambers and equipment. The lab will benefit the university's resident experts, who already have carved careers out of snow and ice, allowing them to take their work to a new level and solidifying MSU's place in the global cold science community.

A niche best served cold

Photo by Kelly Gorham.

For some, it's an annoyance; for others, it's recreation. But for Ed Adams, snow is, above all, a material.

"A lot of people are very confused that I would be out of the engineering department," Adams said. "But, basically, I look at snow as an engineering material. It does a lot of the same things that other materials do; it just happens to do them at different temperature ranges."

In recent years, Adams has focused on the weak layers in snow that cause avalanches. He wants to understand why ice crystals near the snow's surface change shape, a phenomenon similar to what happens when you leave a snowball in the freezer for a few days.

Given the right conditions, a layer of strong snow can become brittle and weak in a matter of hours, Adams said. If that weak layer forms on a steep enough slope and then gets buried with more snow, it becomes an avalanche waiting to happen.

By observing the conditions that cause crystals to change, Adams hopes to determine when weak layers are likely to form. Combining this research with weather observations and topographic maps could provide avalanche experts and ski patrollers with new tools to keep the slopes safe.

Before the Subzero Lab, much of this research was done in a windowless laboratory in MSU's Cobleigh Hall. There, a closet-sized cold chamber provided a home for snow samples while Adams and his team watched what happened to the snow's crystals.

The problem with this kind of research was always a lack of space, Adams said. Apart from the closet-sized chamber, there were only two other large chambers on campus--one made of wood and another designed for food storage--and a handful of tiny ones.

Storage was also a concern. The university's main cold locker was full of ice cores and snow samples from around the world. Open the door, and an ice core might fall on your foot.

So, Adams and MSU polar biologist John Priscu decided to expand. In 2006, the pair wrote a proposal for the Subzero Lab that was endorsed by cold scientists from around the world. The proposal secured $2 million to build the lab, chiefly from the National Science Foundation and the Murdock Charitable Trust. Now complete, the facility houses temperature-controlled instruments, biological incubators, sample preparation space and, most importantly, eight room-sized cold chambers.

Each chamber has its own features, Adams said. One offers lamps for sun and sky simulation; another will have a steel-reinforced strong floor for materials and machinery testing. A germ-free clean room will serve microbiologists studying ice cores, and temperature-controlled plumbing will help simulate cold weather wetlands. On top of that, the facility will have ample storage space and room for class visits.

"We're in Montana, and people expect us to be cold," Adams said. "We should be really established in that, and I think we can really establish a niche with the cold."

Cold stone, concrete & steel

On the ground behind Cobleigh Hall, civil engineer Jerry Stephens shows off a yard-long block of concrete. He acknowledges that concrete isn't the hottest scientific topic, but most of the country's transportation infrastructure is built of the stuff, making it vital to millions of people every day.

The half-ton block is a model of part of a concrete bridge deck similar to those spanning the interstates in Montana. Stephens and his team spent weeks testing the block, studying its durability under the weight of traffic, de-icing chemicals and the cold.

Cold chamber testing is important in Montana, where bridge decks tend to last only two-thirds as long as their predicted life spans. And with new bridge surfaces costing around $2 million, it's important to make sure they last as long as possible.

Doctoral researcher Andrew Slaughter examines the crystal size and structure in snow that has been subjected to metamorphism in one of MSU's cold chambers. Photo by Kelly Gorham.

Many of the materials Stephens studies were too large for the university's old cold chambers, forcing Stephens to craft scale models or to use custom-built chambers that fit around only a portion of their samples. But miniaturizing a bridge deck for testing is difficult. The models must behave as their full-sized counterparts do in strength, durability, friction and other parameters. Everything down to the rebar inside the concrete must be scaled.

"The closer an experiment can come to reality, the better it will help us come up with more cost-effective ways to make bridge decks last longer," Stephens said.

The Subzero Lab, with its larger cold space, will allow Stephens to test bridge materials at full scale, helping scientists find more cost-effective ways to make bridge decks last longer. The lab also will allow versatility in testing. "One day testing a piece of bridge deck and the next day testing a beam or part of a retaining wall," Stephens said.

In addition to bridge decks, Stephens will use the Subzero Lab to test emerging bridge materials, such as carbon-fiber reinforcing rods, beams formed from soybean extracts and concrete made with powdered ice instead of water. Many of these new products claim the same features as their bulkier predecessors, but with less material.

"For years we have overbuilt," Stephens said. "We can't really do that anymore."

In the guts of a glacier

At the bottom of a five-meter pit at the end of a 15-meter tunnel cut into the base of an Antarctic glacier, MSU earth scientist Mark Skidmore has been busy making giant ice cubes.

"When you chain saw into the base of a glacier, you're actually going into the guts of that glacier," Skidmore said.

Skidmore is interested in whether microbes in ice near the base of glaciers are active in the tiny veins between ice crystals, where it hasn't been warmer than -15 degrees Celsius in the past 50,000 years.

To study these habitats, Skidmore cuts blocks of ice, rather than traditional cylindrical ice cores. The blocks provide 20 times more material from a single layer than cores do, meaning more measurements and more opportunities to reproduce experiments in the lab.

Skidmore and graduate student Scott Montross used to travel to a lab in Belgium to cut and process ice samples. The Subzero Lab will allow Skidmore to slice most of his samples on campus, which will get them into the lab for analysis more quickly.

Skidmore also studies whether microorganisms are active in the water-saturated sediments beneath alpine and Arctic glaciers and large ice sheets in Antarctica and Greenland.

Skidmore believes these microbes speed up the chemical weathering of minerals in the sediments beneath ice masses. His findings are helping drive a shift in people's ideas about how life beneath ice helps shape the world. Over the past five years, he has visited glaciers around the world, filling his laboratory freezers with ice from Alaska, Switzerland and Canada.

"The old idea about continental weathering during ice ages, if we go back 10 years, was that, oh well, there's an ice sheet on top of the continent. It's frozen: nothing's happening," Skidmore said. "But our work is changing people's concept of microbial habitats and how important microbially driven processes are, especially in cold regions of our planet that were previously overlooked or ignored for microbial activity."

Studying polar clouds

MSU doctoral student Pat Staron (left) and Ed Adams use a thermal imaging camera to determine the variation in temperature on the surface of snow. The observations help create a thermal map of the snow based on field samples, digital elevation maps and landscape features. Photo by Kelly Gorham.

Joe Shaw knows what it takes to build scientific instruments that work in the world's coldest places. Most recently, his infrared cloud imager, ICI, has photographed some of the hardest-to-study clouds on the planet: those shrouding the Arctic in winter.

"I like to plan for 60 below at the very least," the MSU electrical engineer said. "For really critical designs, 70 below is a good target."

Shaw designed ICI to sit on the roof of a research station in frigid Barrow, Alaska, 320 miles north of the Arctic Circle. There, the device measures the infrared radiation absorbed by the thick polar clouds.

Clouds are a dominant piece of the climate puzzle, Shaw said, because they change the way the atmosphere reflects and transmits solar energy. Climatologists are interested in polar clouds because those extreme regions are especially sensitive to climate changes.

"All the climate models predict that climate change will show up first and most profoundly in the high-latitude polar regions," Shaw said.

But polar clouds have been hard to study with ground-based observers and satellites. Shaw hopes ICI will fare better, producing data that will help scientists more accurately model how the climate maintains a balance of incoming solar and outgoing thermal energy.

All this hinges on building an instrument that can be left for long periods in a place where the temperature gets above freezing only about 100 days a year, where the cold changes how metals conduct electricity and alters how photographic lenses capture images.

"The problem is simply, mechanically, how can you build an instrument that can operate in those cold temperatures without destroying itself?" Shaw said.

Each component must be tested for cold weather tolerance. Cables, cameras, circuit boards and mechanical parts all spend hundreds of hours in temperature-controlled chambers, cycling from warmth to extreme cold over and over.

Laborious, sure, but skipping this cold calibration could put ICI's data off by as much as 20 percent, Shaw said, wasting time and funding. Shaw used to test in MSU's smaller cold chambers, but with the Subzero Lab, he can test more of ICI's components at once, reducing the number of calibration problems.

"If you're going to do this kind of work, you have to have a cold facility," Shaw said.

Life in the ice

For 24 years, John Priscu has found life within and beneath the Antarctic ice. Over that time, his work has helped demolish the once widely held belief that Antarctica was a lifeless waste.

"It's a bit unheard of for there to be that much real estate on our planet that has nothing alive," Priscu said. "But that was the general feeling until not too long ago."

His work has focused on the continent's subglacial lakes, especially Lake Vostok. There, microorganisms live as deep as two and a half miles below the surface, surviving on nutrients carried by summer runoff.

Cold environments are more than places for life just to survive, Priscu said. They're ideal places for life to originate--which contradicts the classic image of life originating in a hot, bubbly pool.

That realization led Priscu to another aspect of his work: the search for life elsewhere in the solar system. Priscu believes that if sediment-rich, "dirty" ice behaves on Mars and the Jovian moon Europa as it does in Antarctica, then there's a good chance extraterrestrial ice will harbor some kind of life.

Priscu's not the only biologist looking at life in the ice. Across campus at MSU's Center for Biofilm Engineering, Christine Foreman also studies Antarctic microbes to learn how organisms living in ice manage to get enough nutrients to survive.

One type of bacterial environment Foreman studies is cryoconites, mini-entombed biofilms on the surface of glaciers. When parts of the glacier melt during warm periods, microbes and organic matter from those biofilms can be carried with runoff water into under-ice lakes where they become food for other microorganisms.

"You're pushing the limits of life with freeze-thaw cycling," Foreman said. "It's very hard on membranes, like getting frostbite too many times. That's why a lot of the extreme environments you come across in the world are only inhabited by microbes."

To study these bacteria, Foreman works with the biofilm center's microscopist Betsey Pitts to take cross-sectional images--about 50,000 of them per inch. When reassembled, these form a three-dimensional map of the bacteria.

Foreman now uses the Subzero Lab's cryostage refrigerated microscope and the lab's clean room to study the organisms' life cycles. Understanding those cycles could expand scientists' understanding of the global climate and food chain, she said.

But that's not the only reason Foreman studies in the cold. To her, ice is more than just research fodder.

Avalanche science

There's not a lot of data about what avalanches do to human bodies. Usually, there's only a death count.

"There is very little information on what happens to people who survive avalanches," said Robb Larson, an assistant professor of mechanical and industrial engineering.

"There are some very interesting engineering questions regarding avalanche loads and forces, and what kinds of injuries they would cause," Larson said. "That information might support the design of safety or rescue equipment to mitigate the non-fatal injuries suffered by an avalanche victim."

In early 2008, Larson, three MSU engineering undergraduate students, including his son Scott of Bozeman, Chad McCammon of Bend, Ore., and Alex Yudell of Northbrook, Ill., along with civil engineering professor Ed Adams, explored those questions by hauling a crash-test dummy to Bridger Bowl ski resort and watching an avalanche tumble it down a slope.

The previous summer, Larson, along with McCammon and Yudell, equipped the dummy with sensors in its head, ankle, knee, femur and tibia to monitor force and torque. Data were gathered by an on-board computer and saved for later analysis.

Though the dummy needs more testing and engineering, the experience has been invaluable for McCammon and Yudell.

"It's great MSU has opportunities for undergraduates like this," Yudell said. "This gets you excited about engineering--to do something that's never been done before, to do real research."